KR20070037876A - Lithography apparatus - Google Patents

Abstract

The present invention relates to an exposure apparatus. An exposure apparatus according to the present invention includes a table on which a substrate is seated, a projection lens for projecting a projection beam onto the substrate, and a confining member defining a liquid in a space between the substrate and the projection lens. The confinement member defines a space in which the liquid is located. Mounted on one side of the limiting member, there is provided a removal means for removing the residue of the liquid out of the space. According to the present invention, liquid residues do not occur on the wafer, thereby preventing defects that may occur.

Immersion exposure apparatus, limiting member, projection lens

Description

Exposure apparatus {Lithography Apparatus}

1 is a view schematically showing an immersion exposure apparatus according to the prior art,

2 is a view schematically showing an immersion exposure apparatus according to the present invention;

FIG. 3 is an enlarged view of portion A of FIG. 2.

♧ explanation of the reference numerals for the main parts of the drawing.

110: table 130: projection lens

150: limiting member 160: removal means

170: liquid inlet 180: first vacuum inlet

185: second vacuum inlet 190: first gas inlet

195: second gas inlet

W: Wafer R: Liquid Residue

L: Liquid

 The present invention relates to a semiconductor manufacturing apparatus, and more particularly to an exposure apparatus.

Photolithography is a process of uniformly applying a photoresist onto a wafer and a process of exposing the pattern on a mask or reticle onto the photoresist on the wafer using an exposure apparatus such as a stepper. And developing the exposed photoresist to form a photoresist having a desired pattern.

Among these, the exposure process is a key process for increasing the degree of integration of semiconductors. In particular, in order to reduce the size of the pattern, the wavelength of the light source used must be shortened. Recently, an exposure light source has been changed from a KrF excimer laser having a wavelength of 248 nm to an ArF excimer laser having a wavelength of 193 nm. Furthermore, research on the use of new light rays such as X-rays, electron beams, and ion beams as an Extreme Ultra-Violet (EUV) light source is being conducted to develop nano semiconductor devices having a line width of 100 nm or less.

In addition, an immersion exposure technique has been developed for disposing a liquid having a constant refractive index between the projection lens and the wafer to improve the resolution and depth of focus. Immersion exposure apparatus for ArF currently uses water to increase the refractive index of the projection light passing through the projection lens. The water must be in direct contact with the projection lens and the photoresist on the wafer, for which the immersion exposure apparatus is provided with an immersion hood which can confine the water between the projection lens and the wafer.

1 is a view schematically showing an immersion exposure apparatus according to the prior art.

Referring to FIG. 1, the immersion exposure apparatus 10 includes a table 11 on which the wafer W is seated and a projection lens 13 on which light irradiated onto the wafer W is projected. The immersion exposure apparatus 10 has an immersion hood 15 unlike the general exposure apparatus. The immersion hood 15 blocks water L that is supplied between the wafer W and the projection lens 13 from flowing out. The immersion hood 15 is provided with a liquid inlet 17, a vacuum inlet 19, and a gas inlet 18. The liquid inlet 17 supplies water L into the immersion hood 15 from the liquid supply unit (not shown), and the gas inlet 18 prevents the supplied water L from leaving the interior of the immersion hood 15. Inject. In addition, the vacuum suction port 19 sucks the water L leaving the inside of the immersion hood 15. Therefore, the gas inlet 18 and the vacuum inlet 19 serve to prevent the droplet R from occurring on the wafer W as the wafer W is moved after the exposure process is performed. However, the water L in the immersion hood 15 cannot be completely prevented from flowing out by the gas inlet 18 and the vacuum inlet 19. The water R flowing out to the outside generates defects such as reaction with the photosensitive film on the wafer W. This can reduce the yield.

The present invention has been proposed in consideration of the above-mentioned situation, and a technical problem to be achieved by the present invention is to provide an exposure apparatus capable of preventing a defect from occurring on a wafer by a liquid used in an immersion exposure process. .

The exposure apparatus according to the present invention for achieving the above technical problem is provided with a removal means for removing the liquid residue that can cause defects in the wafer. An exposure apparatus according to an embodiment of the present invention comprises a table on which the substrate is seated; A projection lens for projecting a projection beam onto the substrate; A confinement member defining a liquid in a space between the substrate and the projection lens; And removal means mounted to one side of the confinement member and capable of removing the residue of the liquid out of the space.

According to the present invention, since the residue of the liquid is removed by the removing means, no defect occurs in the wafer.

In this embodiment, the confining member includes a liquid inlet for supplying the liquid, a first gas inlet for injecting a gas for confining the liquid to the space, and a first vacuum inlet for sucking the liquid out of the space. Include. And, the removing means includes a second vacuum suction port for suctioning the residue of the liquid out of the space without being sucked by the first vacuum suction port.

In addition, the removal means may further include a second gas inlet, the second gas inlet is located on one side of the second vacuum inlet to inject a gas to push the residue of the liquid toward the second vacuum inlet direction can do. In this embodiment, the second gas inlet may be located between the second vacuum inlet and the confining member, and may be inclined in a direction opposite to the direction in which the gas is injected.

The liquid may be water or a fluid having a refractive index greater than that of water.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the spirit of the present invention to those skilled in the art will fully convey.

Although terms such as first and second are used to describe a vacuum inlet or a gas inlet in the embodiments of the present specification, the vacuum inlet or the gas inlet should not be limited by these terms. These terms are only used to distinguish one given vacuum inlet or gas inlet from another vacuum inlet or gas inlet.

In the drawings, the size of components, etc. may be exaggerated for clarity. The same reference numerals throughout the specification represent the same components.

2 is a view schematically illustrating an immersion exposure apparatus according to the present invention, and FIG. 3 is an enlarged view of portion A of FIG. 2.

2 and 3, the immersion exposure apparatus 100 includes a table 110, a projection lens 130, and a confining member 150. Although not shown, the immersion exposure apparatus 100 may further include an illumination system that provides projection light, a photomask that serves to pattern the projection light according to a predetermined pattern, and a support structure that supports the photomask.

The liquid L is supplied between the wafer W and the projection lens 130 seated on the table 110. The liquid L may be water or a fluid having a larger refractive index than water. The liquid L is injected into the confining member 150 through the liquid inlet 170 from the liquid supply part (not shown). The injected liquid L is in direct contact with the projection lens 130 and the wafer W. Since the projection light passing through the projection lens 130 is refracted by the liquid (L) medium having a large refractive index, the resolution and the depth of focus can be secured even if the design rule is reduced.

In addition to the liquid inlet 170, the first gas inlet 180 and the first vacuum inlet 190 may be disposed in the confining member 150. In addition, a liquid outlet (not shown) through which the injected liquid L is discharged may be disposed. The first gas injection hole 180 injects gas such that the liquid L does not leave the confining member 150. In addition, the first vacuum suction port 190 sucks the liquid L which leaves the inside of the confining member 150. As such, the first gas inlet 180 and the first vacuum inlet 190 prevent liquid L from escaping from the confining member 150, but cannot completely block the encapsulation.

The removing unit 160 is disposed on one side of the limiting member 150 of the exposure apparatus 100 according to the present invention. The removal means 160 includes a second vacuum inlet 195. In addition, the removal means 160 may further include a second gas inlet 185. The removal means 160 is positioned in the direction in which the wafer W moves during the exposure process. That is, as shown in FIG. 2, when the wafer W moves from the left side to the right side, the removing unit 160 is positioned on the right side of the limiting member 150 so as to finally pass through the wafer W having undergone the exposure process. do.

At this time, the liquid residues R leaving the confining member 150 are removed by the removing means 160. When the gas injected from the second gas inlet 185 is pushed toward the second vacuum inlet 195 while drying the liquid residue R, the second vacuum inlet 195 remains undried and the liquid residue R remains. A) remove by suction. The gas injected by the second gas inlet 185 may be inclined to effectively push the liquid residue R toward the second vacuum inlet 195. At this time, the inclined direction is opposite to the direction in which the wafer W moves. If the immersion exposure apparatus 100 moves without moving the wafer W, the direction in which the exposure apparatus 100 moves is inclined.

Arrows in FIG. 3 indicate the direction of movement of the liquid or gas.

On the other hand, in the detailed description of the present invention has been described with respect to specific embodiments, various modifications are of course possible without departing from the scope of the invention.

Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be defined not only by the claims below but also by the equivalents of the claims of the present invention.

According to the present invention described above, the liquid used as the medium for refracting the projection light in the immersion exposure apparatus can be prevented from being separated from the limiting member. Accordingly, liquid residues do not occur on the wafer, thereby preventing defects that may occur.

Claims (7)

A table on which the substrate is seated; A projection lens for projecting a projection beam onto the substrate; A confinement member defining a liquid in a space between the substrate and the projection lens; And And a removal means mounted to one side of the confinement member and capable of removing the residue of the liquid out of the space. The method of claim 1, The limiting member, And a first gas inlet for injecting the liquid to supply the liquid, a first gas inlet for injecting a gas to confine the liquid to the space, and a first vacuum inlet to suck the liquid out of the space. The method of claim 2, The removal means, And a second vacuum suction port for sucking the residue of the liquid out of the space without being sucked by the first vacuum suction port. The method of claim 3, wherein The removal means further includes a second gas inlet, The second gas inlet is located on one side of the second vacuum inlet for injecting a gas for pushing the residue of the liquid toward the second vacuum inlet direction. The method of claim 4, wherein And the second gas inlet is located between the second vacuum inlet and the confining member. The method of claim 4, wherein The second gas injection hole is disposed to be inclined in a direction opposite to the direction in which the gas is injected. The method of claim 1, And said liquid is water or a fluid having a refractive index greater than that of water.

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